A disc image is a single file or set of data containing the complete contents and structure of a data storage device, such as a hard drive. Disc images are often created as system backups, or for deployment of commercial application programs or for audio/video content. Disc images are often stored on destination devices that record the images on compact discs (CDs) or digital versatile discs (DVDs), which may be sensitive to the rate at which the data is delivered.
If the data is provided to such destination devices at a rate slower than the destination device optimally records the data, buffer under-run can occur. When buffer under-run occurs, physical damage can occur to the physical media of the destination device, because the destination device must wait for more data to be provided. While the destination device is waiting for more data, the writing element of the device, such as the laser in optical disc drives, may burn the media in a manner that renders the media unreadable.